A known technique for separating constituents of a mixture, referred to as simulated moving bed (SMB) or simulated countercurrent (SCC) technique, consists in passing the mixture into a set of columns arranged in series and comprising each beds filled with an adsorbent. A complex assembly of pumps, lines and valves makes it possible to establish through the beds a fluid circulation allowing injection of a feed from which at least one constituent is to be separated and of an eluent containing chiefly the desorbent, or withdrawal of an extract containing chiefly the preferably adsorbed constituent or of a raffinate mainly consisting of the least preferably adsorbed elements. Such a system is for example described in patent FR-2,762,793.
It is not possible in a SCC to circulate the solid phase. It is simulated by means of a complex set of valves and pumps controlled according to complicated algorithms. Periodic replacement of the solid phases in the columns is extremely costly and requires relatively long production stops. This type of system is difficult to manage because of the complexity thereof. Its maintenance is also heavy.
Another known technique for separating constituents A and B in solution in a liquid mixture consists in injecting it into a “chromatographic column” subjected to a centrifugal force, which is designed to allow one of the liquid phases to be percolated through the other liquid phase and vice versa (chromatography referred to as CCC or CPC).
In practice, as shown notably in patents FR-2,791,578, U.S. Pat. No. 4,551,251, U.S. Pat. No. 4,877,523 or U.S. Pat. No. 4,857,187, this type of system comprises one or more piles of disks D driven in rotation (see FIG. 4). Each one comprises in the thickness thereof and over its entire periphery a succession of cells CE laid out in a radial or oblique direction and arranged in series by a set of circuits of fine winding lines L at the ends of each cell. The circuits of all the disks communicate with one another. The cells and their communication circuits are filled with a stationary liquid phase kept in place by the centrifugal force and another mobile liquid phase that percolates through the stationary phase.